In storing documents onto photosensitive material such as microfiche, a large number of documents are copied on rolls of photographic film. It is desirable to minimize the need for operations personal to continually change out cartridges. It is also desirable for cartridges containing photographic film to have a large capacity and not require frequent change out.
There are four basic types of construction methods for light tight film containers used to dispense web rolls. The first type is complicated and requires many parts to manufacture. It usually contains rollers, doors or other devices inside the cartridge, and the web roll. How these cartridges are constructed varies, however, a typical example is shown in U.S. Pat. No. 5,565,959. A second type of cartridge uses three basic parts, two end caps which contain a flexible or semi-flexible body. An example of this type is shown in U.S. Pat. No. 5,275,283. A third type of cartridge is a two piece box split at the exit slot to facilitate installing the light lock material and web roll. A typical example of this type cartridge is shown in U.S. Pat. No. 5,193,759. The fourth type of cartridge is a box with an insert inside that supports the web role. The last flap, which closes on the box, is usually the light lock area. An example of the fourth type of cartridge is U.S. Pat. No. 5,246,111.
There are advantages and disadvantages to each type of cartridge described. For example, type I cartridges tend to have excellent performance and long life but can have a significant cost. They tend to be used in situations where the web roll can be loaded into cartridges in a light free environment. Heavy rolls and wide rolls can be easily adapted to type I cartridges.
Type II cartridges tend to be used for wider rolls that are light or medium weight. They are cost-effective but care must be used to avoid accidentally opening the light lock area and exposing the roll of film. The fastening method sometimes involves glue which can also cause photographic reactions due to the out gassing of the glue as it hardens.
Type III cartridges tend to be used with narrow, medium, or heavy weight rolls. They can also be used as a reasonable compromise for long life and cost effectiveness. Unfortunately, for large diameter heavy web rolls, the tooling costs can be extremely high driving up the unit cost. However, they are rather effective for medium weight rolls. A high volume of this type of cartridge is required in order for the product to be cost effective.
Type IV cartridges are suitable for use with light weight rolls only. They are also restricted to narrow width rolls due to the extreme flexibility of the light lock flap. Simply picking up the cartridge may expose a wider roll to light by bending the light lock area. Heavy rolls can not be used in a cardboard or paperboard box of this type. Another problem associated with this type of cartridge is maintaining light integrity at all the corners and seams because of the weight of heavy rolls.
As market pressures cause manufacturers to reduce the price of microfiche film, there is a need for a very large diameter, narrow width, web roll, packaged in a low-cost cartridge. Currently the market does not offer this option.